Network slicing is an emerging concept, where a single physical network supports multiple logical networks called slices. Network slices may be isolated from each other, so that a failure of one network slice may not impact another network slice.
Currently it is not possible to inform a mobile entity, also called user entity or UE hereinafter, during attach or other UE-network interactions about the supported slices and APNs (Access Point Names). If the UE does not provide an APN, the UE is informed about the default APN in EPC (Evolved Packet Core) during initial attach. The present situation is as follows:                The UE does not provide an APN during initial attach and the network assigns a default APN based on subscription (and the UE is informed which APN is assigned), or        The UE provides an APN during initial attach or when requesting PDN connection establishment. The network checks whether the APN is part of the subscription, and in case of roaming, the network may check whether it is part of the roaming agreement.        
The network may also reject the initial attach or PDN (Packet Data Network) connection establishment if the requested APN is not known or not allowed for this subscriber. This is causing unnecessary signaling between UE and network until the UE has found out via try and error which APNs are supported in the currently used PLMN. If adding the support of network slices, then there will be further interactions between UE and network until both UE and network are “in agreement”.
Accordingly, a need exists to avoid the above mentioned problems and to minimize a signalling between the mobile entity and the mobile communications network.